Biopolymers

Biological Hierarchy

Molecules form cells
cells form tissues
tissues form organs
organs form organisms
organisms form a population
populations form species
species form a biosphere

Lipids

The ones that attach to the cell membrane have an organic group, a phosphate group before the glycerol and saturated fatty acid and unsaturated fatty acid
The ones with only saturated fatty acids are closely packed and form a decent cell membrane bilayer
The ones that are unsaturated have bent strands and that causes them to be loosely packed
the above is the actual phospholipid bilayer structure
The one strand that is unsaturated keeps the bilayer flexible
Sterol molecules separate phospholipid bilayers:

Carbohydrates

starch polymer is formed from glucose
We've covered this elsewhere

Nucleic acid

Inside the cell theres a nucleus
Inside the nucleus, there are chromosomes
Inside the chromosomes, there are coiled chromatins
Inside the coiled chromatin there are DNA double helix
DNA is basically a polyelectrolyte since it has a negative charge. Histones are used to neutralise this negative charge
The negative charge is formed due to phosphates

Proteins

Amino Acids -
The amino acids basic structure is basically the same. They only vary in R
There are a minimum of 2 pKa for this. One of them is in the range of 9-10 and the other is 2-3, This is because of the two functional groups. The 9-10 one is of the NH2 group and the 2-3 one is for the COOH
Zwitterionic is when both charges are present on the molecule
Each protein has a name, structure, three letter code, one letter code and functional group
For example: Tyrosine, Tyr, Y, aromatic, hydroxyl
If the R group is simply one hydrogen, you get Glycine
If it's methyl, you get alanine
If it's isopropyl, you get valine
If it's isobutyl, you get leucine
Simple phenyl group, you get phenylalanine
methanol, you get Serine
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In professors ppt, the polar molecules are just limited to serine, threonine, tyrosine, asparagine and glutamine. The others, which are given in our polar section are in the non polar section
So Glycine, Cysteine are non polar
Cystine is basically two cysteines linked together
Disulfides are very temperature stable
Isoelectric point is the pH where the net charge on the molecule is 0
It lies between pK1 and pK2

Peptide bonds

two amino acids can combine and form peptide bonds between themselves
pheylalanine, cysteine, glycine would be:
FCG is the code for the protein here
- Phe Cys Gly
The ends of the polypeptide chain are called the amine terminus and carboxy terminus

Function of Proteins

- Enzymes - biological catalyst
- Regulators of catalysis - hormones
- Transport and store O2, metal ions, sugars, lipids, etc
- Contractile Assemblies - muscle fibers, separation o chromosomes, etc
- Sensory - Rhodopsin, nerve proteins
- Cellular defense - immunoglobins, antibodies, killer T cell, receptors
- Structural - collagen, silk, etc.

The function of the protein is determined by the protein structure

Protein structure

The secondary structure: alpha helix, beta sheets, random coils and beta turns
alpha helix ^
Tertiary structure forms because the side chains "don't like water". t's the 3D structure of an entire peptide
Quarternary structure is how the tertiary structures come together